The length of a rectangular playing field is three times the width. If the perimeter of the playing field is $96$ m, what is the area of the field in square meters?
Say the length and width are $l$ and $3l$, respectively. Then the perimeter is $96 = l + 3l + l + 3l = 8l$. So, $l = \frac{96}{8} = 12$. So, the area is $12\cdot 36 = \boxed{432}$.